Governor gearshift control device



Oct. 14, .1941

'L. s. PFOST 2,259,114

' GOVERNOR GEARSHIFT CONTROL DEVICE Filed Jan. 24, 1938 2 Sheets-Sheet 1 Oct. 14, 1941'. s. PFOST GOVERNOR GEARSHIFT CONTROL DEVICE 2 Sheets-Sheet 2 Filed Jan. 24, 1938 FIG. 2

lA/VEN 7'01-1 LESTER 5. PFosT ATTORNEY Patented Oct. 14, 1941 UNITED STATES PATENT OFFICE 1,259,1i4ff f. e v e GOVERNOR GEARSHIFT C DNTROLDEVICE Lester S. Pfost, Racine,;Wis., assignor to The Massey-Harris Company, Racine, Wis., a corporation of Maryland I Application January 24, 1938, Serial No. 186,605

2Claims. rota-4'72) v The present invention relates to a tractor gear shift having a connection to a two speed engine governor and means whereby the governor is automatically thrown into and out of high speed when the gear shift is moved into and out of high tractor speed. v g

More belt power should be available than is necessary or desirable for driving the tractor; I therefore provide ,what I term a twin power tractor, one power being suitable for driving the tractor at low-field work speed and the other for belt service and high road speed, each being governor controlled. I accomplish these objects by providing a belt drive pulley of a diameter and speed ratiowhich requires a higher engine speed and power than the engine speed and power required for tractor draw bar work.

Modern tractors are now equipped with pneumatic tires, therefore it is customary to proin my device being possible only in high gear.

Thus the tractor may be caused to travel at high speed but the high engine speed is not available except when the transmission is in high gear in which position a dangerous pullingtorque is not possible because of the high speed ratio.

I also provide means whereby when the tractor engine is used for belt power purposes, and after the high speed governor control has been made operative, the gear shift will be automatically locked in its neutral position to thereby prevent accidentally throwing the gears'into mesh. 7 v

Generally stated, the objects of the present invention are to provide means, whereby the tractor may be more convenient to operate, safer and more economical and adaptable to a greater range of usefullness on the farm and roadway.

To these and other useful ends the present invention consists of parts, combinations of parts or their equivalents, and mode of operation, as herein-after described,;and claimed and shown in the accompanying. drawings in which:

Fig. 1 is a side elevation of atractor equipped with one form of my invention, having the near rear wheel removed. Fig. 2 is an enlarged partially sectioned side view of the part of the high gear shift mechanismillustrated in Figure 1 and having means whereby the governor speed is increased automatically when the high gear is. thrown into mesh. and reduced again to normal when this gear'is thrown out of mesh.

Fig. 3 is an enlarged fractional view of a modification.

Fig. 4 is a partially sectioned top view of the ing of member Cf.

device shown in-Figure 3 including a fraction of the control rod and its guiding tube.

Fig. 5 illustrates fractionally the engaging end of the gearshift lever and its locking means as i applied :to Figures 3 and 4.

Fig. 6 illustratesin vertical section the design of agovernor adapted for use with the present invention.

As thus illustrated, I have shown the preferred formof' my invention wherein the tractor is designated by reference character A. The engine speed controlling governor is designated by reference character B and the mechanism connected to the engine speed governor and the gear shift is designated by reference character C. The engine in Figure 1 is designated by reference character D. Governor B may be any form ofcentrifugal type which may be adjusted normally to cause the engine D to turn at say 1100 R. P. M. Governor B is preferably mounted within an oil tight housing and is provided with a control member [0 which is slidably mounted in and protrudes through the housing as illustrated.

An operating connection is made between the governor and thegear shifting device by means of bell crank l|, rod I3 and lever 14. Lever I4 is mounted'on a shaft I5.

I provide a conventional third and fourth tractor speed gear shift shaft I6. I provide a forwardly-projecting lever H which is suitably secured to shaft l5. A rod i8 is provided which contacts arm I l and rests on shaft I6 as indicated. Rod] 8 is slidably mounted in the hous- H I provide a projection I9 in a cover lid 20 having an opening in which spring 2! is positioned, the spring being long enough to exert considerable pressure on shaft 16 through rod l8.

I provide a steel ball 22 having a suitably mounted pressure spring 23. Shaft I6 is provided with four depressions 24, 25, 26 and 21. Depressions 24,25 and 2B are suitably positioned wherebyball 22 will hold the rod against accidental movement; when in neutral, high and third gear shift positions. Shaft 16 is illustrated as being in its neutral position. When this shaft is moved so depression 24 is under ball 22,,it maybe considered as being in positionfor third or next to high speed gear, and when depression 26, is under ball 22, the shaft maybe considered as in high gear position for road-travel. I 1

1 By scrutinizing Figure 2 it will be noted that when gear shift shaft I6 is moved to high gear position, rod l8 will be forced into depression 21 by spring2l; thus lever l4 at its lower end will be moved rearwardly, and as a result, rod I3 will be moved rearward'ly and cause bell crank II to press member [0 downward. The

and that when this high gear is again shifted out of mesh, member ID will be raised and the governor will then cause the engine to turn at its normal speed. a I

Clearly the action of thedevi'ce will be automatic and when the high gear ratio is used, the engine speed will be increased so as to make the tractor suitable for road travel. In all other operations of the gear shift, the engine speed will clearly be normal or the speed best adapted for draw-bar service.

Referring now to Figures 3 and 4, wherein a somewhat different form of controlling unit is used in place of unit C. The unit in its entirety is designated by reference character E. The object of this modification is primarily to form a cooperating connection between the gear shift and governor the same as in unit C except that in unit E provision is made for manually increasing the engine speed to say 1400 R. P. M. However, as illustrated in Figures 3 and 4, means are provided whereby the governor cannot be shifted to its high speed except when the gear shifting means is in neutral or in high.

. In these modifications, the gear shifting lever 30 is mounted as is customary in devices of the class on a ball 3| having the usual rubber shield 32. The depending arm 33 is made to operatively engage the gear shifting mechanism' and move the various gears into mesh according to the position of lever 30. In Figure 3 I have illustrated this rod as being in neutral position, the device being viewed from the right side of the tractor.

I provide 9. depending lever 34 having at its lower end a horizontally positioned member 35, this member being slotted as at 33. Member 34 is secured to a rotatably mounted shaft 31, on the free end of which is secured a lever 38, the outer end of this lever being provided with a spring actuated member 39 (see Figure 4). This spring is designed to press the protruding end 43 of member 39 into one of two openings 4| or .42. One opening is positioned to hold member 33 in its neutral position as shown in Figure 4.

Member l3 in this design is secured to member 38 and extends at right angle rearwardly through a guide tube I 3a whereby when the fork is moved so as to engage member 33 while in neutral, rod I3 will cause bell crank H to force member I of the governor downwardly, thus to increase the speed of the governor to 1400 R. P. M., at which time the gear shift will be held in its neutral position, thus the engine will be prepared for belt service and there will be no danger of accidentally shifting the gears into mesh during this time.

In Figure 6 I illustrate in vertical section the design of a governor which may be used with my device'wherein numeral 45 designates the housing into which the governor is mounted and having a vertically positioned shaft 46 adapted to be driven by a bevel pinion 41 in any suitable manner from the crank or cam shaft of the engine. Head 48 is slidably mounted on shaft 52 being secured to its protruding end as shown. 'A- rod 53 operatively connects lever 52 to the power valve at the carburator as illustrated in Figure 1. I provide two weights 54-54 having arms which are pivotally mounted on head 48 as at 55-55. Two tension springs 5'! (one not shown) are secured to opposite sides of weights 54 thus to act against centrifugal force.

A member ID is slidably mounted in the top of housing 45, the lower end having rotatably mounted thereon a collar 59, this collar being connected to weights 54 by means of links 60-50. Member 10 is provided with an orifice Bl (see dotted lines) into which the reduced end of shaft 46 is slidably journaled. Bell crank H as shown, is operatively connected to member ID by means of a pin 62, members I0 and H each having suitable slots for the purpose, the near portion formed by the slot in member [0 being removed so as to expose to view the slot in member I I. 4

Thus it will be seen that member ID will be raisedor lowered according to the position of bell crank H. Member 48 is shown in a medial position. That is, it is operating the engine at normal load but at high speed. If, however, it is desired to operate the engine at low speed, then arm 38 will b moved to the position shown in Figure 4 so member ID will be moved to its highest position.

Clearly the principal object of the present invention is to form a connection between the gear shift and the governor control. Therefore, obviously, various combinations or connections to the gear shift may be made other than those shown and described. For example, in Figure 5, I have illustrated the position assumed by arm 33 when the transmission is set into high gear or for road work, wherein a slot 36A in arm 34A may be made to lock the high gear into position after the governor has been set manually to operate the engine at high speed.

It will also be understood that other combinations and arrangements of the parts may be used without departing from the spirit and scope of the present invention as recited in the appended claims.

Having thus shown and described the preferred form of my invention I claim:

1. A tractor of the class described, including a two-speed governor controlled engine and a gear shift transmission, a connection between said governor and transmission and means whereby the high speed transmission gear shift position only will permit the governor to operate the engine at its high speed.

2. A tractor of the class described, comprising an engine having a two speed governor there for, a gear shift transmission, a connection between said gear shift transmission and said governor and means whereby the high speed transmission position will shift the governor to high speed, and whereby the governor will cause the engine to turn at normal speed when said gear shift is not in its high speed position.

' LESTER S. PFOST. 

